Voter identification laws, adopted by states in recent years amid concerns about fraud, are getting mixed reviews as courts weigh whether they unconstitutionally keep some people from the polls.

State courts in Georgia and Missouri last fall invalidated laws that required voters to show photo ID each time they cast ballots. Georgia and Missouri are among 11 states that have passed such laws since 2003, inspired partly by allegations of voter fraud raised in Florida and elsewhere during the 2000 elections.

The Georgia law, blocked by federal and state judges, required people to show one of six government-issued forms of photo identification, such as a driver's license or passport. In the most recent challenge to the law, brought by voters who said they couldn't cast ballots because they did not have photo IDs, a judge ruled in September that Georgia's requirement put an unconstitutional condition on voting. Previously, state polling places had long accepted utility bills, bank statements and other types of non-photo ID as proof of residency.

In October, Missouri's Supreme Court struck down the state's requirement that registered voters show a state or federal photo ID to cast a ballot. The judges said the law was an illegal hurdle for poor, elderly and disabled residents.

Elsewhere, however, federal appeals courts have not been as willing to reject voter ID laws.

On Jan. 4, a three-judge panel of the U.S. Court of Appeals for the 7th Circuit upheld Indiana's law requiring voters show photo ID in each election. Voting 2-1, the panel rejected claims by the state Democratic Party and others that the law violates the voting rights of those without easy access to such IDs.

Even as they upheld Indiana's law, Judge Richard Posner, joined by Judge Diane Sykes, cited the politics surrounding voter ID laws. "Most people who don't have photo ID are low on the economic ladder and … are more likely to vote for Democratic than Republican candidates," Posner wrote. He noted, however, that it's difficult to maneuver today without a photo ID and that "the vast majority of adults" have one.

Dissenting Judge Terence Evans sharply criticized the law: "Let's not beat around the bush: The Indiana voter photo ID law is a not-too-thinly-veiled attempt to discourage Election Day turnout by certain folks believed to skew Democratic."

Meanwhile, a three-judge panel of the U.S. Court of Appeals for the 9th Circuit has expressed skepticism about arguments that Arizona's voter ID law should be thrown out. The Arizona law is widely viewed as the nation's strictest because it requires voters to prove they are not just state residents, but also U.S. citizens.

Thomas Hudson, attorney for a group of challengers, told the appeals panel Jan. 8 that the law is like a poll tax because of the cost to Native Americans and others who may have difficulty obtaining birth certificates, passports or other documents to prove citizenship. The judges, who have not issued an opinion in the case, asked for evidence of the law's impact — including whether there was any record of how many Native Americans did not have IDs that would prove citizenship.

Hudson said he believed "thousands" of Native Americans could be affected but acknowledged that specific evidence had not been gathered. The 9th Circuit judges suggested by their questions that they would return the case to a trial court to get such answers.

"Much of the future litigation will be about finding real people who are adversely affected" by ID policies, says Richard Hasen, a professor at Loyola Law School in Los Angeles who specializes in election law. He adds, however, "There is not yet very good empirical evidence" to support either side: that many voters are being disenfranchised by ID requirements or that voter fraud is rampant.